Golf 16V Idle Revs High - ISV Faulty?

Over the last few days my VW Golf GTI 16V has started to rev much higher than normal at idle or in traffic so rather than 1000rpm it can jump to 2000rpm or more.

Interestingly a problem that I'd had with the idle not holding when the engine was cold for the first 30 seconds or so has now resolved itself so I'm guessing the two are linked.

I've disconnected the ISV (Idle Stabilisation Valve) and the engine now idles correctly when warm - but still struggles when cold first thing.

Looks like more investigation needed this weekend!


Golf Mk2 GTI 16V Revs high at Idle